Received in revised form

er demonstrates the r seat in a simulated. All rights reserved. the energy through a stroking load limit mechanism. This mech-anism allows the seat and the occupant to move at loads just under the humanly tolerable limit, over the maximum distance between the seat pan and the cabin floor (Coltman, 1994). The seat pant mass and can designed energy Standard-58095A (1986) is the standard used for aircrew seat design. It sets the condition that a crashworthy seat must be designed to carry an occupant with 5 kg of equipment during a crash. Current body-borne equipment can exceed six times that depending on mission type (NAVAIR 13-1-6.7.2, 1999). If the increased mass causes the impact energy to be excessive, a phenomenon called bottoming out will occur at the end of stroke. Bottoming out oc-curs, because the stroke is initiated at lower acceleration and causes the seat to reach its full stroking distance before the total Abbreviations: DOF, degrees of freedom; ATD, anthropomorphic test device; EQM, equations of motion